JP6520710B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire in which a band-shaped sound absorbing material is adhered to a region corresponding to a tread portion of the inner surface of the tire, and more specifically, reduces the shear strain generated on the adhesive surface of the sound absorbing material and suppresses peeling of the sound absorbing material It relates to a pneumatic tire that made it possible.

  In a pneumatic tire, one of the causes of noise generation is cavity resonance due to vibration of air filled inside the tire. The hollow resonance noise is generated when the tread portion vibrates due to the unevenness of the road surface when the tire is rolled, and the vibration of the tread portion vibrates the air inside the tire.

  As a method of reducing noise due to such cavity resonance phenomenon, it has been proposed to dispose a sound absorbing material in a cavity formed between the tire and the rim of the wheel. More specifically, a band-shaped sound absorbing material is adhered to a region corresponding to the tread portion on the inner surface of the tire (see, for example, Patent Documents 1 and 2).

  However, in a pneumatic tire, expansion due to inflation and diameter growth due to centrifugal force at the time of high-speed traveling occur, which causes shear strain on the bonding surface of the sound absorbing material. In addition, although the tread portion is deformed at the time of contact with the ground, such deformation also causes shear distortion in the bonding surface of the sound absorbing material. Then, if the bonding surface of the sound absorbing material bonded to the tire inner surface is repeatedly subjected to shear strain over a long period of time, there is a problem that the sound absorbing material peels off from the tire inner surface.

Japanese Patent Application Laid-Open No. 2002-67608 Japanese Patent Application Laid-Open No. 2005-138760

  An object of the present invention is to make it possible to reduce shear strain generated on the adhesive surface of a sound absorbing material and to suppress peeling of the sound absorbing material when bonding a band-shaped sound absorbing material to a region corresponding to a tread portion of the tire inner surface It is in providing a pneumatic tire.

A pneumatic tire according to the present invention for solving the above object comprises a tread portion extending in the circumferential direction of the tire to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and the sidewall portions. A pneumatic tire having a band-shaped sound absorbing material bonded to a region corresponding to the tread portion on the inner surface of the tire via a bonding layer in a region corresponding to the tread portion on the inner surface of the tire. A bonding area bonded to the inner surface of the tire and a non-bonding area not bonded to the inner surface of the tire are provided on the bonding surface of the sound absorbing material, and the bonding area is divided into a plurality of circumferential areas by the non-bonding area. together is divided into zones, said sound absorbing material has a missing portion in at least one location in the tire circumferential direction, the missing portion and the non-contact regions spaced apart from each other in the tire circumferential direction located When the total number of the missing part and the noncontact area is n, the reference arrangement angle α is 360 ° / n, the tolerance angle β is 90 ° / n, and the missing part and the noncontact area The actual arrangement angle .theta. Is set to .alpha .-. Beta..ltoreq..theta..ltoreq..alpha. +. Beta .

  In the pneumatic tire according to the present invention, a band-shaped sound absorbing material is bonded to a region corresponding to the tread portion of the inner surface of the tire along the circumferential direction of the tire via an adhesive layer. By dividing the bonding area into a plurality of areas in the tire circumferential direction by the non-bonding area, sound absorption due to expansion due to inflation, diameter growth due to centrifugal force during high-speed running, and deformation of the tread portion upon grounding It is possible to reduce the shear strain generated on the adhesive surface of the material and to suppress the peeling of the sound absorbing material. As a result, the noise reduction effect based on the sound absorbing material can be maintained for a long time.

  In the present invention, it is preferable that the non-bonded area has a shape that overlaps the virtual straight line orthogonal to the tire circumferential direction and the entire width of the sound absorbing material. That is, the non-bonded area may extend mainly along the tire width direction. By this, it is possible to effectively reduce the shear strain generated on the adhesive surface of the sound absorbing material.

  In addition to dividing the bonded area into a plurality of areas in the tire circumferential direction by the non-bonded area, it is preferable to divide the bonded area into a plurality of areas in the tire width direction by the non-bonded area. In this case, in addition to the shear strain in the tire circumferential direction, the shear strain in the tire width direction can be effectively alleviated.

  The sound absorbing material is a single sound absorbing material extending in the circumferential direction of the tire, and has a uniform thickness at least in a range corresponding to the adhesive surface in a cross section orthogonal to the longitudinal direction, and the cross sectional shape is along the longitudinal direction It is preferable to be constant. Thereby, the volume of the sound absorbing material per bonding area can be maximized, and an excellent noise reduction effect can be obtained. Moreover, since the sound absorbing material having such a shape is easy to process, its manufacturing cost is low.

  The ratio of the volume of the sound absorbing material to the volume of the cavity formed in the tire at the time of rim assembly is preferably greater than 20%. As described above, by increasing the volume of the sound absorbing material, an excellent noise reduction effect can be obtained, and even with a large sound absorbing material, a good bonding state can be ensured over a long period of time. The volume of the hollow portion is the volume of the hollow portion formed between the tire and the rim in a state where the tire is rimmed on the regular rim and filled with the regular internal pressure. The “regular rim” is a rim that defines the standard for each tire in the standard system including the standard on which the tire is based, for example, the standard rim for JATMA, “Design Rim” for the TRA, or ETRTO In the case of “Measuring Rim”. However, in the case where the tire is a new car-mounted tire, the volume of the hollow portion is determined using a genuine wheel on which the tire is assembled. The “normal internal pressure” is the air pressure specified by each standard in the standard system including the standard to which the tire is based, and in the case of JATMA, the maximum air pressure, in the case of TRA, the table “TIRE ROAD LIMITS AT VARIOUS In the case of ETRTO, the maximum value described in "COLD INFlation PRESSURES" is "INFLATION PRESSURE", but when the tire is a new car-mounted tire, the air pressure displayed on the vehicle is used.

  The hardness of the sound absorbing material is preferably 60 N to 170 N, and the tensile strength of the sound absorbing material is preferably 60 kPa to 180 kPa or more. A sound absorbing material having such physical properties is excellent in durability to shear strain. The hardness of the sound absorbing material is measured in accordance with JIS-K 6400-2 "Soft foam material-Physical characteristics-Part 2: Determination of hardness and compressive stress-strain characteristics", and D It is measured by the method (a method of determining the force after 20 seconds by 25% constant compression). Further, the tensile strength of the sound absorbing material is measured in accordance with JIS-K 6400-5 "Soft foam material-Physical characteristics-Part 5: Determination of tensile strength, elongation and tear strength".

  The sound absorbing material preferably has a missing portion at at least one location in the tire circumferential direction. By providing such a missing portion, it is possible to effectively reduce the shear strain generated on the adhesive surface of the sound absorbing material.

  When the dropout portion and the non-contact area are spaced apart from each other in the tire circumferential direction, the total number of the dropout portion and the non-contact area is n, the reference position angle α is 360 ° / n, and the tolerance angle β Is preferably 90 ° / n, and the actual arrangement angle θ of the missing portion and the non-contact area is α-β ≦ θ ≦ α + β. By this, it is possible to effectively reduce the shear strain generated on the adhesive surface of the sound absorbing material.

  The adhesive layer is preferably a double-sided adhesive tape, and the peel adhesion thereof is preferably in the range of 8 N / 20 mm to 40 N / 20 mm. As a result, it is possible to easily perform the attaching operation of the sound absorbing material and the disassembling operation at the time of discarding the tire while keeping the fixing strength of the sound absorbing material favorably. The peel adhesion of the double-sided adhesive tape is measured in accordance with JIS-Z0237. That is, the double-sided pressure-sensitive adhesive sheet is backed by laminating a 25 μm-thick PET film. The backed adhesive sheet is cut into a square of 20 mm × 200 mm to prepare a test piece. The release liner is peeled off from the test piece, and the exposed adhesive surface is attached to a stainless steel (SUS: B304, surface finish BA) plate as an adherend by causing a 2-kg roller to make one reciprocation. After maintaining this in an environment of 23 ° C. and RH 50% for 30 minutes, using a tensile tester, in accordance with JIS Z 0237, under an environment of 23 ° C. and RH 50%, peeling angle 180 °, tensile speed 300 mm / min. Under the following conditions, the 180 ° peel adhesion to the SUS plate is measured.

FIG. 1 is a perspective sectional view showing a pneumatic tire according to an embodiment of the present invention. FIG. 2 is an equatorial line sectional view showing a pneumatic tire according to an embodiment of the present invention. FIG. 3 is a developed view showing an example of a sound absorbing material adhered to the inner surface of the pneumatic tire of the present invention. FIG. 4 is a development view showing a modification of the sound absorbing material adhered to the inner surface of the pneumatic tire of the present invention. FIG. 5 is a developed view showing another modification of the sound absorbing material adhered to the inner surface of the pneumatic tire of the present invention. FIG. 6 is a developed view showing another modified example of the sound absorbing material bonded to the inner surface of the pneumatic tire of the present invention. FIG. 7 is a developed view showing another modification of the sound absorbing material bonded to the inner surface of the pneumatic tire of the present invention. FIG. 8 is an equatorial line sectional view showing a pneumatic tire according to another embodiment of the present invention. FIG. 9 is an equatorial line sectional view showing a pneumatic tire according to another embodiment of the present invention. FIG. 10 is an equatorial line sectional view showing a pneumatic tire according to another embodiment of the present invention. FIG. 11 is an equatorial line sectional view showing a pneumatic tire according to another embodiment of the present invention. FIG. 12 is an equatorial line sectional view showing a pneumatic tire according to another embodiment of the present invention.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the attached drawings. 1 and 2 show a pneumatic tire according to an embodiment of the present invention. In FIG. 1, the pneumatic tire according to the present embodiment includes a tread portion 1 extending in the circumferential direction of the tire to form an annular shape, a pair of sidewall portions 2 disposed on both sides of the tread portion 1, and the sidewalls And a pair of bead portions 3 disposed on the inner side in the tire radial direction of the portion 2.

  In the pneumatic tire, a band-like sound absorbing material 6 is adhered to a region corresponding to the tread portion 1 of the tire inner surface 4 via the adhesive layer 5 along the tire circumferential direction. The sound absorbing material 6 is made of a porous material having open cells, and has a predetermined sound absorbing property based on the porous structure. As a porous material of the sound absorbing material 6, it is preferable to use foamed polyurethane. On the other hand, a paste-like adhesive or a double-sided adhesive tape can be used as the adhesive layer 5.

  FIG. 3 shows an example of the sound absorbing material 6 bonded to the inner surface of the pneumatic tire of the present invention. In FIG. 3, Tc is a tire circumferential direction, and Tw is a tire width direction. As shown in FIG. 3, on the bonding surface (the surface on the outer side in the tire radial direction) of the sound absorbing material 6, a bonding region 6A bonded to the tire inner surface 4 and a non-bonding region 6B not bonded to the tire inner surface 4 And are provided. The non-adhesive area 6B is an area where the sound absorbing material 6 is not fixed to the tire inner surface 4 and may be an area where the adhesive layer 5 is locally excluded or, for example, the adhesive surface of the sound absorbing material 6 After the adhesive layer 5 is provided on the entire area of the substrate, the adhesive strength may be locally canceled. The non-bonded area 6 B traverses the sound absorbing material 6 at the longitudinal middle portion of the sound absorbing material 6 over the entire width. As a result, the bonded area 6A is divided into a plurality of areas in the tire circumferential direction by the non-bonded area 6B.

  In the pneumatic tire described above, when the band-shaped sound absorbing material 6 is bonded to the area corresponding to the tread portion 1 of the tire inner surface 4 via the adhesive layer 5 along the tire circumferential direction, the bonding area on the bonding surface of the sound absorbing material 6 6A and the non-adhesion region 6B are provided, and the adhesion region 6A is divided into a plurality of areas in the tire circumferential direction by the non-adhesion region 6B. When a shear strain is generated on the adhesive surface of the sound absorbing material 6 due to the deformation of the tread portion 1, the shear strain can be alleviated. That is, if the bonding area 6A becomes longer in the tire circumferential direction, shear strain accompanying the circumferential length change of the tread portion 1 becomes larger, but by dividing the bonding area 6A into a plurality of areas in the tire circumferential direction by the non-bonding area 6B Distortion can be reduced. As a result, peeling of the sound absorbing material 6 can be suppressed, and the noise reduction effect based on the sound absorbing material 6 can be maintained for a long time.

  The non-bonded area 6A needs to be provided at at least one place in the sound absorbing material 6, but may be provided at a plurality of places in the longitudinal direction of the sound absorbing material 6. Moreover, as for the distance D of the tire peripheral direction of the divisions of the adhesion | attachment area | region 6A divided | segmented by 6 A of non-adhesion area | regions, it is desirable to set to the range of 10 mm-80 mm. If the distance D is less than 10 mm, the effect of alleviating shear strain is reduced. If the distance D exceeds 80 mm, the sound absorbing material 6 tends to move, which causes deterioration of the durability.

  FIG. 4 shows a modification of the sound absorbing material 6 bonded to the inner surface of the pneumatic tire of the present invention. Unlike the example of FIG. 3 in which the plan view shape of the non-bonded area 6B is rectangular, the plan view shape of the non-bonded area 6B is a parallelogram in the example of FIG. In any case, the non-bonded area 6B has a shape that overlaps the virtual straight line L orthogonal to the tire circumferential direction Tc and the entire width of the sound absorbing material 6. That is, the non-bonded area 6 B extends along the tire width direction Tw and crosses the sound absorbing material 6. Thereby, it is possible to effectively reduce the shear strain generated on the adhesive surface of the sound absorbing material 6. In particular, it is preferable to employ a rectangle or parallelogram which satisfies the definition based on the virtual straight line L.

  FIG. 5 shows another modification of the sound absorbing material 6 bonded to the inner surface of the pneumatic tire of the present invention. In FIG. 5, non-adhesive regions 6 </ b> A are provided at two locations in the longitudinal direction of the sound absorbing material 6. Of course, the number of non-bonded areas 6A to the sound absorbing material 6 may be further increased.

  6 and 7 show another modification of the sound absorbing material 6 bonded to the inner surface of the pneumatic tire of the present invention. In FIG. 6 and FIG. 7, a non-bonded area 6 </ b> B having a cross shape is formed on the bonded surface of the sound absorbing material 6. That is, the non-bonded area 6 B traverses the sound absorbing material 6 across the entire width in the longitudinal middle portion of the sound absorbing member 6 and longitudinally cuts the sound absorbing material 6 in the middle in the width direction of the sound absorbing member 6. As a result, the bonded area 6A is divided into a plurality of areas in the tire circumferential direction by the non-bonded area 6B, and is divided into a plurality of areas in the tire width direction by the non-bonded area 6B. In this case, in addition to the shear strain in the tire circumferential direction, the shear strain in the tire width direction can be effectively alleviated.

  In the pneumatic tire, the single sound absorbing material 6 extends in the tire circumferential direction, and the sound absorbing material 6 has a uniform thickness at least in a range corresponding to the bonding surface in a cross section orthogonal to the longitudinal direction Preferably, the cross-sectional shape is constant along the longitudinal direction. In particular, the cross-sectional shape in a cross section orthogonal to the longitudinal direction of the sound absorbing material 6 is preferably a rectangle (including a square), but in some cases, it may be an inverted trapezoid where the bonding surface side becomes narrow. . Thereby, the capacity of the sound absorbing material 6 per bonding area can be maximized, and an excellent noise reduction effect can be obtained. In addition, since the sound absorbing material 6 having such a shape is easy to process, the manufacturing cost is low.

  When the pneumatic tire is assembled in a rim, a cavity 7 is formed between the tire inner surface 4 and the rim, but the ratio of the volume of the sound absorbing material 6 to the volume of the cavity 7 is greater than 20% preferable. As described above, by increasing the volume of the sound absorbing material 6, an excellent noise reduction effect can be obtained, and even with the large sound absorbing material 6, a good bonding state can be ensured for a long time. The width of the sound absorbing material 6 is preferably in the range of 30% to 90% of the tire contact width.

  The hardness (JIS-K6400-2) of the sound absorbing material 6 is preferably 60 N to 170 N, and the tensile strength (JIS-K 6400-5) of the sound absorbing material 6 is preferably 60 kPa to 180 kPa. The sound absorbing material 6 having such physical properties is excellent in durability against shear strain. If the hardness or tensile strength of the sound absorbing material 6 is too small, the durability of the sound absorbing material 6 will be reduced. In particular, the hardness of the sound absorbing material 6 is preferably 70 N to 160 N, and more preferably 80 N to 140 N. The tensile strength of the sound absorbing material 6 is preferably 75 kPa to 165 kPa, and more preferably 90 kPa to 150 kPa.

  Further, as shown in FIG. 2, it is preferable that the sound absorbing material 6 have a missing portion 8 at at least one location in the tire circumferential direction. The missing portion 8 is a portion where the sound absorbing material 6 does not exist on the tire circumference. In addition to providing the non-bonded area 6 B on the adhesive surface of the sound absorbing material 6, the shear strain generated on the adhesive surface of the sound absorbing material 6 can be effectively alleviated by providing the lack portion 8 on the sound absorbing material 6. Such a missing portion 8 may be provided at one place or at three to five places on the tire circumference. That is, when the missing parts 8 are provided at two places on the tire circumference, the deterioration of the tire uniformity becomes remarkable due to mass imbalance, and when the missing parts 8 are provided at six places or more on the tire circumference, the manufacturing cost increases. It becomes remarkable.

  When the missing parts 8 are provided at two or more locations on the tire circumference, the sound absorbing material 6 is interrupted in the tire circumferential direction, but even in such a case, the adhesive layer 5 made of, for example, a double-sided adhesive tape If the plurality of sound absorbing members 6 are connected to each other by another laminate such as this, these sound absorbing members 6 can be handled as an integral member, so that the work of attaching to the inner surface of the tire can be easily performed. Can.

  8 to 12 show a pneumatic tire according to another embodiment of the present invention. In the embodiment shown in FIG. 2, the non-bonded area 6B is provided at one place in the longitudinal direction of the sound absorbing material 6, but in the embodiment shown in FIG. 8, the non-bonded areas 6B are provided at two places in the longitudinal direction of the sound absorbing material 6. In the embodiment shown in FIG. 9, the non-adhesive regions 6B are provided at three locations in the longitudinal direction of the sound absorbing material 6, and in the embodiment shown in FIG. 10 the non-adhesive regions 6B are provided at four locations in the longitudinal direction of the sound absorbing material 6. . In particular, it is preferable to provide the non-adhesive regions 6B at one to three places in the longitudinal direction of the sound absorbing material 6. In this case, it is possible to achieve both the relaxation effect of shear strain and the suppression of the manufacturing cost.

  Furthermore, in the embodiment shown in FIG. 11, the missing parts 8 are provided at three locations on the tire circumference, and the non-adhesive regions 6 </ b> B are provided at one location in the longitudinal direction of each sound absorbing material 6. Furthermore, in the embodiment shown in FIG. 12, the missing parts 8 are provided at four locations on the tire circumference, and the non-adhesive regions 6 </ b> B are provided at one location in the longitudinal direction of each sound absorbing material 6.

  In the various embodiments as described above, when the dropouts 8 and the non-contact areas 6B are arranged at intervals in the circumferential direction of the tire, the total number of the dropouts 8 and the non-contact areas 6B is n. Preferably, the arrangement angle α is 360 ° / n, the tolerance error angle β is 90 ° / n, and the actual arrangement angle θ of the missing portion 8 and the non-contact area 6B is α-β ≦ θ ≦ α + β. For example, in the embodiment of FIG. 2 θ = 180 ° ± 45 °, in the embodiment of FIG. 8 θ = 120 ° ± 30 °, and in the embodiment of FIG. 9 θ = 90 ° ± 22.5 ° 10, θ = 72 ° ± 18 ° in the embodiment of FIG. 10, θ = 60 ° ± 15 ° in the embodiment of FIG. 11, and θ = 45 ° ± 11.25 ° in the embodiment of FIG. is there. By arranging the notches 8 and the non-contact areas 6B at substantially equal intervals on the tire circumference in this manner, it is possible to effectively reduce the shear strain generated on the adhesive surface of the sound absorbing material 6. The arrangement angle θ of the missing portion 8 and the noncontact region 6B is an angle measured around the tire rotation axis O, and is an angle based on the center position in the tire circumferential direction of the missing portion 8 and the noncontact region 6B. It is.

  The adhesive layer 5 preferably has a peel adhesion (JIS-Z0237: 2009) in the range of 8 N / 20 mm to 40 N / 20 mm. As a result, it is possible to easily carry out the attaching operation of the sound absorbing material 6 and the disassembling operation at the time of tire disposal while keeping the fixing strength of the sound absorbing material 6 good. That is, when the peeling force of the adhesive layer 5 is too weak, the fixed state of the sound absorbing material 6 becomes unstable, and conversely, when the peeling force of the adhesive layer 5 is too strong, the bonding position is changed in the bonding operation of the sound absorbing material 6 Becomes difficult, and it becomes difficult to tear off the sound absorbing material 6 at the time of tire disposal. In particular, the peel adhesion of the adhesive layer 5 is preferably 9 N / 20 mm to 30 N / 20 mm, more preferably 10 N / 20 mm to 25 N / 20 mm.

  The pneumatic tire described above has tire constituent members such as a carcass layer and an inner liner layer, but the tire constituent members are formed by splicing both end portions of the belt-like members in the tire circumferential direction, and the tire width direction And a splice extending to the When such a tire constituent member is provided, it is preferable to dispose the splice portion in the non-adhesive area 6 B of the sound absorbing material 6. More specifically, the splices may be arranged along a virtual straight line L as shown in FIGS. When the sound absorbing material 6 is adhered to the inner surface 4 of the tire, particularly when using a double-sided adhesive tape, the double-sided adhesive tape may not follow the step of the splice portion during construction and may locally float. Such local adhesion failure may gradually increase as the tread portion is deformed when the tire is running, and the sound absorbing material 6 may eventually come off. On the other hand, by arranging the splice portion of the tire constituent member represented by the carcass layer and the inner liner layer in the non-adhesion region 6B of the sound absorbing material 6, the above-mentioned inconvenience is avoided and the adhesion of the sound absorbing material 6 is achieved. Durability can be secured.

  The tire size is 215 / 45R17, and it is disposed on the inner side in the tire radial direction of a tread portion extending in the circumferential direction of the tire to form an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and these sidewall portions. In a pneumatic tire provided with a pair of bead portions and having a band-shaped sound absorbing material bonded to a region corresponding to the tread portion on the inner surface of the tire along the tire circumferential direction via an adhesive layer, the bonding state of the sound absorbing material is different Tires of Comparative Example 1 and Examples 1 to 3 were produced.

  In Comparative Example 1, a missing portion was provided at one location in the tire circumferential direction of the band-like sound absorbing material, and the entire bonding surface of the sound absorbing material was used as the bonding region.

  In Example 1, a missing portion is provided at one location in the tire circumferential direction of the band-like sound absorbing material, and the bonding area and the non-bonding area are provided on the bonding surface of the sound absorbing material as shown in FIG. The tire circumferential direction was divided into two zones. The arrangement angle θ of the missing part and the non-contact area was 180 °. Moreover, the planar view shape of the non-adhesive area | region was made into the rectangle like FIG.

  In the second embodiment, a missing portion is provided at one location in the tire circumferential direction of the band-like sound absorbing material, and the bonding area and the non-bonding area are provided on the bonding surface of the sound absorbing material as shown in FIG. The tire circumferential direction was divided into two zones. The arrangement angle θ of the missing part and the non-contact area was 180 °. Moreover, the planar view shape of the non-adhesive area | region was made into cross shape like FIG. 6, and the adhesive area | region was divided | segmented into two area in the tire width direction by the non-adhesive area | region.

  In the third embodiment, a missing portion is provided at one position in the tire circumferential direction of the band-like sound absorbing material, and the bonding area and the non-bonding area are provided on the bonding surface of the sound absorbing material as shown in FIG. It was divided into three zones in the tire circumferential direction. The arrangement angle θ of the missing portion and the non-contact area was 120 °. Moreover, the planar view shape of the non-adhesive area | region was made into the rectangle like FIG.

  The following matters were common to Comparative Example 1 and Examples 1 to 3. The cross-sectional shape in the cross section orthogonal to the longitudinal direction of the sound absorbing material is rectangular, and the cross-sectional shape is constant along the tire circumferential direction. The ratio of the volume of the sound absorbing material to the volume of the cavity formed in the tire at the time of rim assembly was 30%. The hardness of the sound absorbing material was 80 N, and the tensile strength of the sound absorbing material was 90 kPa. The peel adhesion of the adhesive layer was 16 N / 20 mm.

  The pneumatic tires of Comparative Example 1 and Examples 1 to 3 were assembled to a wheel of rim size 17 × 7 JJ, respectively, and a running test was conducted for 100 hours with a drum tester under the conditions of air pressure 150 kPa, load 5 kN and speed 150 km / h Then, the presence or absence of adhesion peeling of the sound absorbing material was visually confirmed. In addition, a running test is performed with a drum tester under the same running conditions as above as an index of adhesion peeling resistance, and the presence or absence of bonding peeling of the sound absorbing material is confirmed every 10 hours, and running until adhesion peeling occurs. I determined the distance. The evaluation result of adhesion peeling resistance was shown by the index which sets comparative example 1 to 100. The larger the index value is, the more excellent the adhesion peel resistance is. The results are shown in Table 1.

  As shown in Table 1, in the tire of Comparative Example 1, adhesion peeling of the sound absorbing material occurred remarkably after the running test for 100 hours, but in the tires of Examples 1 to 3 sound absorption after the running test for 100 hours There was no adhesion peeling of the material at all.

  Next, it has the same structure as in Example 1 or 3 except that the hardness of the sound absorbing material, the tensile strength of the sound absorbing material, the peel adhesion strength of the adhesive layer, and the arrangement angle θ of the missing portion and the noncontact area are made different. The tires of Examples 4 to 11 were prepared.

  About the tire of these Examples 4-11, the presence or absence of adhesive peeling of the sound-absorbing material after 100 hours of running tests and adhesive peel resistance were evaluated by the method similar to the above. The results are shown in Table 2.

  As shown in Table 2, in the tires of Examples 4 to 7 in which the hardness of the sound absorbing material, the tensile strength of the sound absorbing material, and the peel adhesion of the adhesive layer were changed, 100 hours were the same as in Example 1 or 3. There was no adhesion peeling of the sound absorbing material at all after running. Further, as apparent from the comparison between Example 8 and Example 9 and the comparison between Example 10 and Example 11, the total number of the missing part and the non-contact area is n, and the reference arrangement angle α is 360 °. Assuming that the tolerance angle .beta. Is 90.degree./n, good results are obtained when the actual arrangement angle .theta. Of the missing part and the non-contact region satisfies .alpha .-. Beta..ltoreq..theta..ltoreq..alpha. +. Beta. .

DESCRIPTION OF SYMBOLS 1 tread part 2 bead part 3 side wall part 4 tire inner surface 5 adhesion layer 6 sound absorbing material 6A adhesion area 6B non-adhesion area 7 hollow part 8 omission part

Claims (9)

A tread portion extending in the circumferential direction of the tire and forming an annular shape, a pair of sidewall portions disposed on both sides of the tread portion, and a pair of bead portions disposed on the tire radial direction inner side of the sidewall portions A pneumatic tire having a band-shaped sound absorbing material bonded to a region of the inner surface of the tire corresponding to the tread portion along the circumferential direction of the tire via an adhesive layer, wherein the bonding surface of the sound absorbing material is adhered to the tire inner surface Bonding area and non-bonding area not bonded to the inner surface of the tire, and the bonding area is divided into a plurality of areas in the tire circumferential direction by the non-bonding area , and the sound absorbing material is at least in the tire circumferential direction. When a missing portion is provided at one place, and the missing portion and the non-contact area are spaced apart from each other in the circumferential direction of the tire, the total of the non-contact area and the missing portion When n is n, the reference arrangement angle α is 360 ° / n, the tolerance error angle β is 90 ° / n, and the actual arrangement angle θ of the missing portion and the non-contact area is α-β ≦ θ ≦ α + β pneumatic tire, characterized in that the the.   The pneumatic tire according to claim 1, characterized in that the non-bonded area has a shape such that an imaginary straight line perpendicular to the circumferential direction of the tire overlaps the entire width of the sound absorbing material.   The pneumatic tire according to claim 1 or 2, wherein the bonded area is divided into a plurality of sections in the tire width direction by the non-bonded area.   The sound absorbing material is a single sound absorbing material extending in the circumferential direction of the tire, and has a uniform thickness at least in a range corresponding to the adhesive surface in a cross section orthogonal to the longitudinal direction, and the cross sectional shape is in the longitudinal direction The pneumatic tire according to any one of claims 1 to 3, wherein the tire is constant.   The pneumatic tire according to any one of claims 1 to 4, wherein the ratio of the volume of the sound absorbing material to the volume of the cavity formed in the tire at the time of rim assembly is greater than 20%.   The pneumatic tire according to any one of claims 1 to 5, wherein the hardness of the sound absorbing material is 60N to 170N, and the tensile strength of the sound absorbing material is 60 kPa to 180 kPa. The pneumatic tire according to any one of claims 1 to 6 , wherein the adhesive layer is made of a double-sided adhesive tape, and the peel adhesion thereof is in the range of 8N / 20mm to 40N / 20mm. The pneumatic tire according to any one of claims 1 to 7 , wherein the sound absorbing material is made of a porous material having open cells. The pneumatic tire according to claim 8 , wherein the porous material is a foamed polyurethane.

Images